Wetting agents in amalgamation



Patented May 13, 1941 WETTING AGENTS 1N AMALGAMATION Kellogg Krebs, Berkeley, and Lee E. Tucker, Monrovia, Calif assignors to American Oyanamid Company, New York, N. Y., a corporation of No Drawing. Application June 27, 1939, Serial No. 281,310

4 Claims.

This invention relates to amalgamation methods of recovering precious metals from ores and other materials containing precious metals. Particularly, it relates to the use of wetting agents in amalgamation.

According to the present'invention, we have found that when ores containing precious metals are treated with wetting agents prior to and/or during amalgamation, the recovery of the [valuable constituents of the ores is increased.

The present invention is not limited to any particular theory as to the action of wetting agents in producing the improved result. The wetting agent may cause more eflicient wetting of the ore pafticles and this may facilitate contact of the precious metal with the amalgam material. In the case of the surface contaminated precious metals, the wetting agent may change the character of the coating to such an extent that the particles are more readily associated with the mercury or amalgam material.

It is an advantage of the present invention that higher recoveries of precious metals by amalgamation are made possible.

It is also an advantage that the process has a wide range of application and is .not limited to the use of any particular wetting agent. Any of the chemical compounds that have wetting power and that are ordinarily used or classified as wetting agents are applicable to the process. While it is understood that all wetting agents produce good results, diilerent wetting agents will vary in the degree to which they produce the improved results.

Wetting agents of the types such as sulfated high molecular alcohols, sulfonatcd esters of higher alcohols and dibasic acids, and the alkylated aryl sulfonates have been found to give good results. Examples of such wetting agents shown to give .the best results include dioctylsulfosuccinic acid salts, sodium isopropylnaphthalene sulfonates, sodium salt of sulfated oleyl alcohol, sodium lauryl sulfate and a reaction product of oleic acid and 2-aminoethane sulfonic acid.

The application of the process will be described in greater detail in conjunction with the use of typical wetting agents as illustrated by the following example:

, Example 600 g. samples of an ore from the-Philippine Islands, containing gold to 600 mesh in particle size), galena, pyrite, chalcopyrite, sphalerite,

limonite, quartz, calcite and an undetermined amount of finely divided slimes were present and assaying about 0.46 to 0.53 oz. Au/ton, were ground to minus mesh, 58% minus 325 mesh. The grinding operation was conducted at 67% solids. The ground pulp was diluted to about 40% solids and treated in separate tests with 1.0 lb./ton sodium isopropylnaphthalene sulfonate and 1.0 lb./ton sodium dioctylsulfosuccinate, respectively. About 30 g. of mercury were added to the pulp and the mixture agitated for 15 minutes on the laboratory rolls. The amalgam and residue were then separated and assayed for gold.

The results of tests with wetting agents were compared with those of a control test conducted in the absence of wetting agents. The results of these amalgamation tests are presented in the following table:

1.0 lb./ton

1.0 lb./ton No weti gggk sodium diting agent naphthalene octylsulfosun-0mm succinate Au in feed .mg 10. 588 10. 819 1 9. 444 Au in amalgam. mg 5. 075 5. 930 4. 930 Au in tailingmg 5. 513 4. 889 4. 514 An recovery in amalgam per cent. 47. 93 54. 81 52. 20

The term wetting agent" as used in this speci- J fication and the claims refers to those organic compounds possessing marked surface activity in aqueous systems. Specifically, it refers to those substances that have good wetting power, penetrating and spreading properties, as distinguished from those having only detergent and foaming properties. Soaps and related substances having detergent and foaming properties are sometimes loosely referred to as wetting agents but the use of the term in its strict sense as is the case in the present application does not include such substances.

What we claim is:

1. A process of amalgamating auriferous main the presence of sodium isopropylnaphthalene sulfonate.

4. A process of recovering precious metals by amalgamation from ores containing substantial quantities of slime which comprises carrying out the amalgamation in the presence of a wetting agent from the group consisting oi sulfated high molecular alcohols, csulionated esters of higher alcohols and di-basic acids, and alkylatecl aryl su1ionates.-

' mmec KREBS. mm E. TUCKER. 

